Observation of the effect of towed rafts of pulpwood on lake and ocean waves led to a systematic investigation at model scale. An empirical equation compatible with wave theory was devised and lines representing this equation together with points representing experimental results are shown for different conditions. An example of the application of the equation to prototype wave action is given. Four box booms with porous fronts, arranged m series, were substituted for the model pulpwood gam and proved to be effective m damping waves.